13-QR2.  List four regions in North America where wave cyclones tend to develop.

    Wave cylones tend to develop (1) in the Great Plains just east of the Rockies, (2) in the Great Basin, just east of the Sierra Nevadas, (3) in the Gulf of Mexico and (4) in the Atlantic, just east of the Carolinas.

13-QR12. What are the sources of energy for a developing cyclone?

    There are three principal energy sources for a developing cyclone:  (1) gravitational potential energy is released as warm air rises and cold air sinks, (2) latent heat is released as water vapor condenses, and (3) a pressure differential does work on air which is convering towards the surface low pressure center, increasing the kinetic energy of that air.

13-QT3. Explain why, at 500 millibars, when cold advection is occurring, the air temperature does not drop as fast as it should. (Hint: What type of ertical air motions are also occurring?

    The cold air is denser than the air it is replacing. It therefore has a tendency to sink and warm in the process.

13-QT7. Why do Pacific storms often redevelop on the eastern side of the Sierra Nevada?

    Lee-side low pressure systems tend to build on the east side of the Sierras, thus reforming storms whose energies have been reduced by their passing over the Sierras.

13-QT9. If polar lows form in cold polar air over water, how is the atmosphere made unstable so that towering convective cumulus clouds can form?

    First, the associated cold air is from the arctic icecap and is tens of degrees colder than the associated cold water, which cannot be colder than 0°C. Thus there is a large temperature differential at the surface. The extremely cold air over the somewhat warmer water, leads to an extreme instability in the lower atmosphere which causes convection to develop. Second, in the ascending air of convective parcels, condensation releases much latent heat which further drives the convective engine of a polar low.

13-PE1. As you refer to the 300-mb chart below,suppose the winds are blowing at a constant speed parallel to the contour lines. (a) On the chart, mark where regions of convergence and divergence are occurring. (b) Put an L on the chart where you might expect to observe a developing mid-latitude storm. (c) Put an H on athe chart where you might expect to observe an anticyclone. (d) In which directions would the mid-latitude cyclone and anticyclone most likely move? (e) In terms of convergence and divergence, what are the necessary conditions for the intensification of the surface mid-latitude storm? For the building of the anticyclone?

(a), (b), (c) See chart. (d) The cyclone would most likely move toward the ENE while the anticyclone would most likely move to the ESE. (e) Storm intensification would require that upper-level divergence exceed surface convergence at the storm's position. Anticyclone building would require that upper-level convergence exceed surface divergence at the anticyclone's position.